People from a long line of vegetarians who stray from the plant-based diet put themselves at greater risk of heart disease and cancer, warns new research.
The study provides the first evolutionary work that traces a higher frequency of a particular mutation in a primarily vegetarian population in Pune, India.
Researchers compared the Indian group to a group of meat-eating Americans from Kansas. By using data from the 1000 Genomes Project, researchers found evidence that the vegetarian diet over many generations may have driven the higher frequency of a mutation in the Indian population.
The mutation (called rs66698963 and found in the FADS2 gene) is an insertion or deletion of a sequence of DNA that regulates the expression of two genes, FADS1 and FADS2.
These two genes are key to making long chain polyunsaturated fats.
Among the long chain fats, arachidonic acid is a key target of the pharmaceutical industry because it is a central culprit for those at risk for heart disease, colon cancer and many other inflammation-related conditions.
Treating individuals according to whether they carry zero, one or two copies of the insertion could be an important consideration for precision medicine and nutrition.
What does it mean?
In simple terms, a mainly plant-based and meat-free diets over a number of generations will reduce the risk of meat related health conditions.
But as soon as you begin to consume animal products, you undo the hard work your ancestors did to protect your health.
The insertion mutation may be favoured in populations eating mainly vegetarian diets and possibly populations that don’t have diets rich in polyunsaturated fats, such as fatty fish.
Interestingly, the deletion of the same sequence might have been adaptive in populations which are based on marine diet, such as the Greenlandic Inuit.
The authors of the study will follow it up with additional worldwide populations to better understand the mutations and these genes as a genetic marker for disease risk.
Dr. Tom Brenna, and Dr. Kumar Kothapalli, two of the srudy leaders, said: ‘With little animal food in the diet, the long chain polyunsaturated fatty acids must be made metabolically from plant PUFA precursors.
‘The physiological demand for arachidonic acid, as well as omega-3 EPA and DHA, in vegetarians is likely to have favored genetics that support efficient synthesis of these key metabolites.
‘Changes in the dietary omega-6 to omega-3 balance may contribute to the increase in chronic disease seen in some developing countries.’
The other leader of the study, Dr. Alon Keinan said it was a very unique scenario of local adaption.
He said: ‘Several previous studies pointed to recent adaption in this region of the genome. Our analysis points to both previous studies and our results being driven by the same insertion of an additional small piece of DNA, an insertion which has a known function.
‘We showed this insertion to be adaptive, hence of high frequency, in Indian and some African populations, which are vegetarian.
‘However, when it reached the Greenlandic Inuit, with their marine diet, it became maladaptive.’
The study was published in the journal Molecular Biology and Evolution.